DENVER, Colorado — President Barack Obama stood in a Denver schoolyard Tuesday imploring Congress to pass his jobs bill, saying it would save teachers the sack and help secure the futures of America's children.

Obama, on a nationwide tour to push the $447 billion legislation, which faces an uncertain fate in Congress, said it would provide jobs for teachers, construction workers and the unemployed.

The bill provides money for state education authorities to keep teachers on the job, as thousands are being laid off due to budget crunches, and calls for spending on work to improve decaying infrastructure, including in schools.

"Thousands of construction workers will have a job again. This is one of the most common sense ideas out there," Obama told a large crowd gathered in outside the school in Denver, Colorado.

He chose the Abraham Lincoln High School in one of the city's less well off suburbs to highlight plans to repair and remodel ageing school classrooms.

"The science labs here at Lincoln High were built decades ago back in the 1960s... science and technology has changed a little bit since the 1960s," he said.

"We need to do everything we can to make sure our kids can compete. Every child deserves a great school and we can give it to them.

"My question to Congress is what on earth are you waiting for?" Obama said.

On the way to the school, Obama's motorcade snaked past the American football stadium where he delivered his soaring acceptance speech at the Democratic National Convention in 2008.

Since then, Obama's star has dimmed in the crucial swing state of Colorado, dragged down by the stagnant economic recovery and fruitless battles with Republicans in Washington's poisoned political atmosphere.

The state is already looming as an important battleground in the 2012 election when Obama will seek a second term in office and Republicans will try to make it a referendum on policies that have failed to pull America out of the economic mire.